1 files changed, 10 insertions, 9 deletions

diff --git a/libavcodec/vp8.c b/libavcodec/vp8.c
index e365877bed..3f07b90b26 100644
--- a/libavcodec/vp8.c
+++ b/libavcodec/vp8.c
@@ -6,20 +6,20 @@
  * Copyright (C) 2010 Jason Garrett-Glaser
  * Copyright (C) 2012 Daniel Kang
  *
- * This file is part of Libav.
+ * This file is part of FFmpeg.
  *
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -117,7 +117,7 @@ static int update_dimensions(VP8Context *s, int width, int height)
     AVCodecContext *avctx = s->avctx;
     int i;
 
-    if (width  != s->avctx->width ||
+    if (width  != s->avctx->width || ((width+15)/16 != s->mb_width || (height+15)/16 != s->mb_height) && s->macroblocks_base ||
         height != s->avctx->height) {
         if (av_image_check_size(width, height, 0, s->avctx))
             return AVERROR_INVALIDDATA;
@@ -384,7 +384,7 @@ static int decode_frame_header(VP8Context *s, const uint8_t *buf, int buf_size)
     }
 
     if (!s->macroblocks_base || /* first frame */
-        width != s->avctx->width || height != s->avctx->height) {
+        width != s->avctx->width || height != s->avctx->height || (width+15)/16 != s->mb_width || (height+15)/16 != s->mb_height) {
         if ((ret = update_dimensions(s, width, height)) < 0)
             return ret;
     }
@@ -700,9 +700,10 @@ void decode_mb_mode(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y,
 {
     VP56RangeCoder *c = &s->c;
 
-    if (s->segmentation.update_map)
-        *segment = vp8_rac_get_tree(c, vp8_segmentid_tree, s->prob->segmentid);
-    else if (s->segmentation.enabled)
+    if (s->segmentation.update_map) {
+        int bit  = vp56_rac_get_prob(c, s->prob->segmentid[0]);
+        *segment = vp56_rac_get_prob(c, s->prob->segmentid[1+bit]) + 2*bit;
+    } else if (s->segmentation.enabled)
         *segment = ref ? *ref : *segment;
     mb->segment = *segment;